The structure and crystallization characteristics of phase change optical disk material Ge1Sb2Te4

The crystallization characteristics of amorphous Ge1Sb2Te4 thin films were studied by means of time‐resolved transition measurements. It was found that a metastable phase appeared at the first stage of the crystallization process and then the metastable phase was transformed into a stable crystalline phase at higher annealing temperatures. The x‐ray diffraction and transmission electron microscopy results indicated the metastable phase was identified as a face‐centered‐cubic structure and the stable crystalline phase corresponded to a hexagonal structure. Our experimental results show that the Ge1Sb2Te4 materials are applicable for phase change erasable optical storage.